A dozen generals and admirals opposed to the government of Venezuelan President Hugo Chavez, and who Tuesday called for the president's resignation, are still defying the elements in a Caracas square, surrounded by civilian supporters. The group is determined to hold out until Mr Chavez quits or holds elections.

The group of 14 senior officers, led by General Enrique Medina, a former military attache in Washington, have declared a policy of disobedience against a government they describe as autocratic and illegitimate.

The group, which has received the support of several dozen, mostly more junior officers, invokes two articles of the country's constitution. These enshrine the right to rebel against any authority or law that violates human rights or the constitution.

Many members of the group were prominent in the events of April 11 to 14, when Mr Chavez was briefly ousted by the military after nineteen people were shot dead during an opposition march.

The government has dismissed them as coup plotters with no backing in the armed forces. The rebel-officers have no command of troops, and say they do not, in any case, favour a coup. But they have called on civilians as well as fellow soldiers to join them in a policy of civil disobedience to force Mr Chavez from power.

Their move caught even many veteran observers of the military by surprise, and has placed the civilian opposition in a difficult position. Less than 24 hours before their pronouncement, a one-day nationwide strike against the government had ended with a call for a referendum on whether the president should stay in power. The decision to collect signatures for the referendum was an important step for the opposition, which has been criticised for not committing itself to a peaceful, democratic solution to the crisis.

The secretary-general of the Organization of American States, Cesar Gaviria, who has been seeking to facilitate a negotiated settlement, condemned the officers' statements. He said they violated the principle of subordination to a legitimate, elected government. But despite the opposition's reluctance to be associated with a military rebellion, it runs the risk of alienating many of its supporters if it keeps its distance.

As a result, the protest seems bound, in the short term, to grow in size.